Quarter	Millions of US Dollars
1971-01-01	30
1971-04-01	30
1971-07-01	54
1971-10-01	85
1972-01-01	201
1972-04-01	337
1972-07-01	407
1972-10-01	654
1973-01-01	746
1973-04-01	960
1973-07-01	1055
1973-10-01	1445
1974-01-01	1577
1974-04-01	1951
1974-07-01	1968
1974-10-01	2101
1975-01-01	2278
1975-04-01	2405
1975-07-01	2398
1975-10-01	2430
1976-01-01	2552
1976-04-01	2726
1976-07-01	2842
1976-10-01	3041
1977-01-01	3355
1977-04-01	3853
1977-07-01	4139
1977-10-01	4759
1978-01-01	5833
1978-04-01	6446
1978-07-01	7034
1978-10-01	7755
1979-01-01	8071
1979-04-01	8233
1979-07-01	8743
1979-10-01	8805
1980-01-01	8304
1980-04-01	9143
1980-07-01	9433
1980-10-01	9359
1981-01-01	9073
1981-04-01	8783
1981-07-01	8929
1981-10-01	9449
1982-01-01	9394
1982-04-01	9079
1982-07-01	9168
1982-10-01	9993
1983-01-01	9531
1983-04-01	9628
1983-07-01	10900
1983-10-01	10855
1984-01-01	11432
1984-04-01	11149
1984-07-01	10962
1984-10-01	11530
1985-01-01	11544
1985-04-01	12432
1985-07-01	13198
1985-10-01	14010
1986-01-01	14759
1986-04-01	15243
1986-07-01	15509
1986-10-01	15068
1987-01-01	15341
1987-04-01	15134
1987-07-01	14941
1987-10-01	16209
1988-01-01	16090
1988-04-01	14872
1988-07-01	14632
1988-10-01	15974
1989-01-01	15361
1989-04-01	14672
1989-07-01	16223
1989-10-01	16342
1990-01-01	50473
1990-04-01	50940
1990-07-01	51694
1990-10-01	67246
1991-01-01	66235
1991-04-01	67189
1991-07-01	68119
1991-10-01	70076
1992-01-01	71824
1992-04-01	72788
1992-07-01	74875
1992-10-01	76264
1993-01-01	77864
1993-04-01	96112
1993-07-01	96700
1993-10-01	108025
1994-01-01	112274
1994-04-01	155017
1994-07-01	162726
1994-10-01	169663
1995-01-01	177370
1995-04-01	180233
1995-07-01	184165
1995-10-01	187650
1996-01-01	193894
1996-04-01	198234
1996-07-01	208376
1996-10-01	214568
1997-01-01	226763
1997-04-01	240757
1997-07-01	245640
1997-10-01	246914
1998-01-01	254312
1998-04-01	270845
1998-07-01	282059
1998-10-01	262442
1999-01-01	264815
1999-04-01	278110
1999-07-01	284840
1999-10-01	293773
2000-01-01	306520
2000-04-01	310832
2000-07-01	343917
2000-10-01	346243
2001-01-01	351682
2001-04-01	347423
2001-07-01	355427
2001-10-01	348309
2002-01-01	354208
2002-04-01	363037
2002-07-01	365642
2002-10-01	369876
2003-01-01	371717
2003-04-01	376560
2003-07-01	383034
2003-10-01	394912
2004-01-01	401324
2004-04-01	406458
2004-07-01	412381
2004-10-01	433088
2005-01-01	440704
2005-04-01	416268
2005-07-01	413015
2005-10-01	418848
2006-01-01	436291
2006-04-01	422572
2006-07-01	426745
2006-10-01	437825
2007-01-01	446064
2007-04-01	448484
2007-07-01	453429
2007-10-01	462564
2008-01-01	467003
2008-04-01	478615
2008-07-01	461196
2008-10-01	448951
2009-01-01	450149
2009-04-01	469103
2009-07-01	484827
2009-10-01	503668
2010-01-01	506480
2010-04-01	510042
2010-07-01	539939
2010-10-01	550003
2011-01-01	569813
2011-04-01	583985
2011-07-01	583742
2011-10-01	589385
2012-01-01	613420
2012-04-01	631037
2012-07-01	647803
2012-10-01	668532
2013-01-01	664067
2013-04-01	670423
2013-07-01	695859
2013-10-01	729789
2014-01-01	730325
2014-04-01	740288
2014-07-01	735693
2014-10-01	734544
2015-01-01	734624
2015-04-01	744011
2015-07-01	751606
2015-10-01	741907
2016-01-01	767702
2016-04-01	824457
2016-07-01	831681
2016-10-01	878491
2017-01-01	921478
2017-04-01	975236
2017-07-01	1005400
2017-10-01	1056380
2018-01-01	1107003
2018-04-01	1127702